Positively cheerful: a survey by the German Economic Institute shows the majority of Germans are very happy with their lives. Photograph: Matthias Schrader/AP

Germany: the country of weltschmerz and angst, a nation constantly terrified of pending nuclear doom and haunted by memories of hyper-inflation, a joyless people prone to "egotism, inferiority complex, sentimentality", as a memo resulting from a meeting between Margaret Thatcher and a group of experts on Germany once put it.

That Germany, if a survey published this week is to be believed, belongs to the history books. According to the report by the German Economic Institute in Cologne, more than half of all German citizens are extremely satisfied with their lives, and only 2% describe their level of contentment as low.

Researchers said that comparably high levels in Germany were recorded only twice previously: at the time of reunification in 1989-90 and during the new-economy boom at the turn of the century.

In one respect, however, the survey confirms an old stereotype: work continues to play a key role in determining the nation's wellbeing. "Individual health and low unemployment rates play a crucial part," said Dominik Enste and Mara Ewers, the authors of the report. "When employment is up, so are satisfaction levels, and vice versa. It's not money that makes people happy, but money earned through their own work."

The data, drawn from a 2012 poll of around 20,000 people, shows that even people out of work had in recent years become more optimistic about finding future employment. Those who did voluntary work once a week were considerably more satisfied with their lives than those who never volunteered.

The happiest Germans live in the north: Hamburg and Schleswig-Holstein registered satisfaction rates of 55% and 53% in the survey, while only 35% of those living in Brandenburg in the old east said they were content with their lives.

Students of theology and sports science had a considerably more optimistic outlook on life than those studying languages, literature and mathematics.

Germany's new identity as Europe's optimists was put to the test tonight when the country faced the USA in the World Cup – they won 1-0. The manager of the American side, Jürgen Klinsmann, a former Germany player and coach is a self-professed advocate of positive thinking, whom the tabloid Bild once nicknamed Grinsi-Klinsi (Grinning Klinsi).